Análise de sensibilidade local do modelo Canegro/DSSAT.

O objetivo deste trabalho é a determinação dos parâmetros que causam variações no CANEGRO, através da análise de sensibilidade, e a sua segregação pela avaliação de quanto sensível é cada parâmetro no modelo estudado. A análise de sensibilidade foi realizada com a cultivar brasileira de cana-de-açúcar SP 89-1115. Foram utilizados dados meteorológicos de temperatura máxima e mínima, precipitação e radiação solar global da estação meteorológica situada na Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), da Universidade de São Paulo (USP) em Piracicaba, SP, Brasil, a 22° 42' 30'' Sul e 47° 38' 00'' Oeste, com altitude de 546 metros

Variation of the speed of light with temperature of the expanding universe

From an extended relativistic dynamics for a particle moving in a cosmic background field with temperature T, we aim to obtain the speed of light with an explicit dependence on the background temperature of the universe. Although finding the speed of light in the early universe much larger than its current value, our approach does not violate the postulate of special relativity. Moreover, it is shown that the high value of the speed of light in the early universe was drastically decreased before the beginning of the inflationary period. So we are led to conclude that the theory of varying speed of light should be questioned as a possible solution of the horizon problem.Comment: 3 pages and 1 figure; Phys. Rev. D86, 027703 (2012

Information, belief and decision: a research perspective of a vertex of managerial behavior

Este artigo é uma revisão preliminar da literatura de uma perspectiva de pesquisa que tem como objetivo estudar o comportamento do decisor, desde o ponto de vista cognitivo e comportamental contemporâneos. A partir de resultados de pesquisas finalizadas, verificase a necessidade de incrementar os estudos a respeito dos aspectos emocionais e afetivos relacionados ao comportamento de decisores, que têm impacto profundo sobre a busca e o uso de informação. Nos estudos cognitivos e comportamentais contemporâneos, as emoções, travestidas em crenças, são consideradas determinantes do comportamento, das interações e das decisões do sujeito. Diante disso, tem-se como perspectiva de pesquisa identificar a relação existente entre as crenças de decisores e a busca e uso de informação, do ponto de vista da gestão da informação e do conhecimento, a partir de fundamentos teóricos da cognição situada e incorporada e da terapia cognitiva, apresentados neste artigo.This article is a preliminary review of the literature from a research perspective that aims to study the behavior of the decision maker, from a contemporary cognitive and behavioral point of view. Based on the results of completed research, there is a need to increase the studies about the emotional and affective aspects related to the behavior of decision makers, which have a profound impact on the search and use of information. In contemporary cognitive and behavioral studies, emotions, transposed into beliefs, are considered determinants of behavior, interactions, and decisions of the subject. In view of this, it is a research perspective to identify the relationship between the beliefs of decision makers and the search and use of information, from the point of view of information management and knowledge, from the theoretical foundations of situated and incorporated cognition and of cognitive therapy, presented in this article.Dossier: Gestión de la información: dilemas y perspectivaFacultad de Humanidades y Ciencias de la Educació

Doubly Special Relativity with a minimum speed and the Uncertainty Principle

The present work aims to search for an implementation of a new symmetry in the space-time by introducing the idea of an invariant minimum speed scale ($V$). Such a lowest limit $V$, being unattainable by the particles, represents a fundamental and preferred reference frame connected to a universal background field (a vacuum energy) that breaks Lorentz symmetry. So there emerges a new principle of symmetry in the space-time at the subatomic level for very low energies close to the background frame ($v\approx V$), providing a fundamental understanding for the uncertainty principle, i.e., the uncertainty relations should emerge from the space-time with an invariant minimum speed.Comment: 10 pages, 8 figures, Correlated paper in: http://www.worldscientific.com/worldscinet/ijmpd?journalTabs=read. arXiv admin note: substantial text overlap with arXiv:physics/0702095, arXiv:0705.4315, arXiv:0709.1727, arXiv:0805.120

EXAFS study of lead-free relaxor ferroelectric BaTi(1-x)Zr(x)O3 at the Zr K-edge

Extended X-ray absorption fine structure (EXAFS) experiments at the Zr K-edge were carried out on perovskite relaxor ferroelectrics BaTi(1-x)Zr(x)O3 (BTZ) (x = 0.25, 0.30, 0.35), and on BaZrO3 for comparison. Structural information up to 4.5 A around the Zr atoms is obtained, revealing that the local structure differs notably from the average Pm-3m cubic structure deduced from X-ray diffraction. In particular, our results show that the distance between Zr atoms and their first oxygen neighbors is independent of the Zr substitution rate x and equal to that measured in BaZrO3, while the X-ray cubic cell parameter increases linearly with x. Furthermore, we show that the Zr atoms tend to segregate in Zr-rich regions. We propose that the relaxor behavior in BTZ is linked to random elastic fields generated by this particular chemical arrangement, rather than to random electric fields as is the case in most relaxors.Comment: 13 pages, 12 figures, 4 tables. Submitted to Phys. Rev.

PTEN mutations are common in sporadic microsatellite stable colorectal cancer

The tumour suppressor gene PTEN, located at chromosome sub-band 10q23.3, encodes a dual-specificity phosphatase that negatively regulates the phosphatidylinositol 3′-kinase (PI3 K)/Akt-dependent cellular survival pathway. PTEN is frequently inactivated in many tumour types including glioblastoma, prostate and endometrial cancers. While initial studies reported that PTEN gene mutations were rare in colorectal cancer, more recent reports have shown an approximate 18% incidence of somatic PTEN mutations in colorectal tumours exhibiting microsatellite instability (MSI+). To verify the role of this gene in colorectal tumorigenesis, we analysed paired normal and tumour DNA from 41 unselected primary sporadic colorectal cancers for PTEN inactivation by mutation and/or allelic loss. We now report PTEN gene mutations in 19.5% (8/41) of tumours and allele loss, including all or part of the PTEN gene, in a further 17% (7/41) of the cases. Both PTEN alleles were affected in over half (9/15) of these cases showing PTEN genetic abnormalities. Using immunohistochemistry, we have further shown that all tumours harbouring PTEN alterations have either reduced or absent PTEN expression and this correlated strongly with later clinical stage of tumour at presentation (P = 0.02). In contrast to previous reports, all but one of the tumours with PTEN gene mutations were microsatellite stable (MSI-), suggesting that PTEN is involved in a distinct pathway of colorectal tumorigenesis that is separate from the pathway of mismatch repair deficiency. This work therefore establishes the importance of PTEN in primary sporadic colorectal cancer

Condutância foliar e transpiração em cafeeiro irrigado de cinco anos de cultivo.

O objetivo deste trabalho foi determinar a condutância estomática e a transpiração de cafeeiro irrigado e sua relação com variáveis climáticas. O experimento foi executado em Piracicaba, SP, Brasil, em cafeeiro cultivar Mundo Novo Apuatã, com 5 anos de plantio, cultivado a pleno sol. As medições nos cinco dias estudados indicaram que a condutância estomática e a transpiração do cafeeiro responderam à variação da temperatura do ar, do saldo de radiação e do vento, sendo mais evidente no dia 24/09/2002. A condutância estomática variou de aproximadamente 0,20 cm s-1 até 0,05 cm s-1 e a transpiração de 6,0 mg m-2s-1 a 0,5 mg m-2s-1 no decorrer dos dias analisados.CBA 2009

Additive noise properties of active matrix flatâ panel imagers

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134764/1/mp6721.pd

Interplay of disorder and antiferromagnetism in TlFe1.6+(Se1−xSx )2 probed by neutron scattering

International audienceThe effect of selenium substitution by sulphur on the structural and physical properties of antiferromagnetic TlFe1.6+δSe2 has been investigated via neutron, x-ray and electron diffraction, and transport measurements. The 5 sqrt(a)× 5sqrt(a)×c super-cell related to the iron vacancy ordering found in the pure TlFe1.6Se2 selenide is also present in the S-doped TlFe1.6+δ(Se1−xSx)2 compounds. Neutron scattering experiments show the occurrence of the same long range magnetic ordering in the whole series i.e. the 'block checkerboard' antiferromagnetic structure. In particular, this is the first detailed study where the crystal structure and the 5 a× 5 a antiferromagnetic structure is characterized by neutron powder diffraction for the pure TlFe1.6+δS2 sulphide over a large temperature range. We demonstrate the strong correlation between occupancies of the crystallographic iron sites, the level of iron vacancy ordering and the occurrence of block antiferromagnetism in the sulphur series. Introducing S into the Se sites also increases the Fe content in TlFe1.6+δ(Se1−xSx)2 which in turn leads to the disappearance of the Fe vacancy ordering at x = 0.5 ± 0.15. However, by reducing the nominal Fe content, the same 5 a× 5 a×c vacancy ordering and antiferromagnetic order can be recovered also in the pure TlFe1.6+δS2 sulphide with a simultaneous reduction in the Néel temperature from 435 K in the selenide TlFe1.75Se2 to 330 K in the sulphide TlFe1.5S2. The magnetic moment remains high at low temperature throughout the full substitution range, which contributes to the absence of superconductivity in these compounds